During the island-hopping campaigns of World War II, military leaders recognized a need for a single organization dedicated to the support of amphibious operations. A decision was made to consolidate amphibious assault assets under one parent command, thus forming Naval Beach Group ONE in July 1948.
Since the beginning, NBG-1 and its component commands have participated in a variety of amphibious operations. Starting early on during the Korean and Vietnam conflicts, to the modern and technically sophisticated amphibious operations in Somalia and Iraq, the Sailors of NBG have served throughout the Pacific and Indian Oceans in support of U.S. policy abroad.
This initial Naval Beach Group (NBG) consisted of Headquarters Unit, Boat Unit One, Amphibious Construction Battalion (ACB) ONE, and Underwater Demolition Team ONE. Eventually, Boat Unit ONE became Assault Craft Unit ONE, and Underwater Demolition Team ONE shifted to the control of Naval Special Warfare Command. In 1949 Beachmaster Unit ONE was added to the organization, and with the addition of Assault Craft Unit FIVE in 1983 the organization gained the ability to conduct over-the-horizon assaults using the landing craft air-cushioned (LCAC).
Amphibious Construction Battalion (ACB) ONE was commissioned at Camp Peary, Williamsburg, Virginia, in July of 1943 as the 104th Naval Construction Battalion. During WWII, the 104th completed many land based construction projects, from air fields to Naval Operation Bases. They first began amphibious missions in 1947, with the assembly and placement of pontoon structures, beach rehabilitation, harbor development, salvage, and training of reservists in these operations. By 1950, the Chief of Naval Operations (CNO) recognized the unique capabilities of the 104th that set them apart from the rest of the Naval Construction Battalions, so they were renamed Amphibious Construction Battalion One.
The capabilities of the Seabees in ACB-1 focus on providing round-the-clock transporting from ship to shore of fuel, materials, equipment and water, in support of the Amphibious Ready Group (ARG), Marine Expeditionary Force (MEF), and Maritime Prepositioning Force (MPF) operations. The importance and impact of these Seabee Battalions was demonstrated during the invasion of Sicily, where it was proven that pontoon causeways provide an excellent method of rapidly unloading vehicle-borne cargo and troops in areas with shallow water where larger ships can’t go, thus providing the element of surprise.
Assault Craft Unit ONE is composed of four utility landing craft (LCU). These rugged steel vessels are used by ARGs to transport cargo, vehicles and troops from amphibious assault ships to the beach or piers. With both bow and stern ramps for loading/offload operations, several LCUs can connect bow to stern to support roll-through offload to shore. Although small in comparison to ships in the fleet, these vessels still have most of the same amenities; including berthing spaces, galley and laundry, and can operate independently at sea for up to ten days.
ACU-1 embarks the well-deck of a larger amphibious ship with the mission to deploy a fighting force of Marines ashore. Ballast tanks on the large amphib are filled, sinking the stern and flooding the well deck, allowing the LCU to float and deploy. ACU handles the amphibious assault aspect of an engagement by moving those troops, vehicles and supplies across open water to the shore.
Since 9/11, ACU-1’s mission has expanded to support the Global War on terrorism. These missions include multi-day anti-piracy patrols, visit-board-search and seizure operations, oil platform defense, humanitarian assistance and disaster relief.
Like many of these support units, Beachmaster Unit ONE was formed to support the amphibious assaults during WWII. It was apparent that the orderly flow of troops, equipment and supplies across the assault beaches was necessary for the success of amphibious operations. This led to the formation of the Beach Party Battalion, which included a Beachmaster Unit. By July 1948 the CNO ordered the commissioning of the Beachmaster Unit as a separate command, forming BMU-1.
BMUs bring tactical components to support amphibious operations. By deploying the Beach Party Team with Expeditionary Forces, BMUs provide beach and surf zone salvage and facilitate the landing and movement on the beach of troops, equipment, supplies and evacuation of casualties, prisoners-of-war and non-combatants. Beachmasters are not only capable of supporting combat operations, as they are also called upon to support humanitarian assistance and disaster relief missions.
Assault Craft Unit FIVE provides the fleet the capability to deliver supplies across long distances in a short period of time with the use of LCACs. The LCAC is a high-speed, over-the-beach, fully amphibious landing craft, capable of hauling 75 tons of cargo (troops, weapon systems, equipment) at speeds of 40+ knots. Although that’s about half the payload capacity of the LCU, the air cushion technology of the LCAC allows it to reach more than 70 percent of the world’s coastline, where LCUs can only access about 15 percent.
As different as these support units are from one another, they all are an integral part of the U.S. fighting forces. They have to operate in a high density, multi-threat environment while deployed with the ARG. All of these units contribute to the core capabilities of U.S. Maritime Sea Power; Forward Presence, Deterrence, Sea Control, Power Projection, and Maritime Security. They work together to provide the fleet with the movement of troops, vehicles, equipment and supplies from ship to shore.
This post originally appeared on iDriveWarships on October 20, 2017 at https://idrivewarships.wordpress.com/2017/10/20/support-units-of-the-amphibious-force/